<!DOCTYPE html>    
<html xmlns="http://www.w3.org/1999/xhtml">    
<head>    
    <title>HTML5 GetUserMedia Demo</title>    
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0" />    
</head>    
<body>    
    <input type="button" title="开启摄像头" value="开启摄像头" onclick="getMedia();" /><br />    
    <video height="120px" autoplay="autoplay"></video><hr />    
    <input type="button" title="拍照" value="拍照" onclick="getPhoto();" /><br />    
    <canvas id="canvas1" height="120px" ></canvas><hr />    
    <input type="button" title="视频" value="视频" onclick="getVedio();" /><br />    
    <canvas id="canvas2" height="120px"></canvas>    
    
    <script type="text/javascript">    
        var video = document.querySelector('video');    
        var audio, audioType;    
    
        var canvas1 = document.getElementById('canvas1');    
        var context1 = canvas1.getContext('2d');    
    
        var canvas2 = document.getElementById('canvas2');    
        var context2 = canvas2.getContext('2d');    
    
        navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;    
        window.URL = window.URL || window.webkitURL || window.mozURL || window.msURL;    
    
        var exArray = []; //存储设备源ID    
        MediaStreamTrack.getSources(function (sourceInfos) {    
            for (var i = 0; i != sourceInfos.length; ++i) {    
                var sourceInfo = sourceInfos[i];    
                //这里会遍历audio,video，所以要加以区分    
                if (sourceInfo.kind === 'video') {    
                    exArray.push(sourceInfo.id);    
                }    
            }    
        });    
    
        function getMedia() {    
            if (navigator.getUserMedia) {    
                navigator.getUserMedia({    
                    'video': {    
                        'optional': [{    
                            'sourceId': exArray[1] //0为前置摄像头，1为后置    
                        }]    
                    },    
                    'audio':true    
                }, successFunc, errorFunc);    //success是获取成功的回调函数    
            }    
            else {    
                alert('Native device media streaming (getUserMedia) not supported in this browser.');    
            }    
        }    
    
        function successFunc(stream) {    
            //alert('Succeed to get media!');    
            if (video.mozSrcObject !== undefined) {    
                //Firefox中，video.mozSrcObject最初为null，而不是未定义的，我们可以靠这个来检测Firefox的支持    
                video.mozSrcObject = stream;    
            }    
            else {    
                video.src = window.URL && window.URL.createObjectURL(stream) || stream;    
            }    
    
            //video.play();    
    
            // 音频    
            audio = new Audio();    
            audioType = getAudioType(audio);    
            if (audioType) {    
                audio.src = 'polaroid.' + audioType;    
                audio.play();    
            }    
        }    
        function errorFunc(e) {    
            alert('Error！'+e);    
        }    
    
            
        // 将视频帧绘制到Canvas对象上,Canvas每60ms切换帧，形成肉眼视频效果    
        function drawVideoAtCanvas(video,context) {    
            window.setInterval(function () {    
                context.drawImage(video, 0, 0,90,120);    
            }, 60);    
        }    
    
        //获取音频格式    
        function getAudioType(element) {    
            if (element.canPlayType) {    
                if (element.canPlayType('audio/mp4; codecs="mp4a.40.5"') !== '') {    
                    return ('aac');    
                } else if (element.canPlayType('audio/ogg; codecs="vorbis"') !== '') {    
                    return ("ogg");    
                }    
            }    
            return false;    
        }    
    
        // vedio播放时触发，绘制vedio帧图像到canvas    
//        video.addEventListener('play', function () {    
//            drawVideoAtCanvas(video, context2);    
//        }, false);    
    
        //拍照    
        function getPhoto() {    
            context1.drawImage(video, 0, 0,90,120); //将video对象内指定的区域捕捉绘制到画布上指定的区域，实现拍照。    
        }    
    
        //视频    
        function getVedio() {    
            drawVideoAtCanvas(video, context2);    
        }    
    
    </script>    
</body>    
</html> 